Resonant waveguide-grating devices and methods for using same

Abstract

Waveguide gratings, biosensors, and methods of using a waveguide grating, including as a biosensor.

What is claimed is: 
     
       1. A method of using a waveguide grating, comprising:
 contacting a waveguide grating with a medium, the waveguide grating being disposed on a substrate and having at least one waveguide layer and at least one grating layer; 
 directing light toward the waveguide grating such that the light contacts the waveguide grating; 
 receiving light that is either reflected from or transmitted through the waveguide grating with a detection unit, the waveguide grating being configured such that a guided-mode resonance peak or minimum occurs in the reflected or transmitted light; 
 using the detection unit to determine an attribute of the received light; and 
 using the attribute to determine at least one parameter of the medium. 
 
     
     
       2. The method of  claim 1 , wherein the light is directed from a laser, a broadband source, or a light emitting diode. 
     
     
       3. The method of  claim 1 , wherein the detection unit comprises a photodetector or an optical spectrum analyzer. 
     
     
       4. The method of  claim 1 , wherein the attribute comprises the spectral content, intensity, phase, or polarization of the received light. 
     
     
       5. The method of  claim 1 , wherein the at least one parameter of the medium comprises the presence or absence of a substance, the quantity of a substance, the refractive index of the medium, or the thickness of the medium. 
     
     
       6. The method of  claim 1 , wherein the medium includes a first parameter and a second parameter, and the using the attribute to determine at least one parameter of the medium includes determining both the first and second parameters using the attribute. 
     
     
       7. The method of  claim 1 , wherein the at least one waveguide layer and the at least one grating layer comprise the same layer. 
     
     
       8. The method of  claim 1 , wherein the attribute comprises a first attribute and a second attribute, the received light has a transverse electric (TE) polarization and a transverse magnetic (TM) polarization, and the method further comprises:
 monitoring the first attribute in the TE polarization of the received light; and 
 monitoring the second attribute in the TM polarization of the received light. 
 
     
     
       9. The method of  claim 1 , where the received light has a transverse electric (TE) polarization and a transverse magnetic (TM) polarization, and the using the attribute comprises monitoring the attribute in the TE polarization and in the TM polarization to determine the at least one parameter of the medium. 
     
     
       10. The method of  claim 9 , where the at least one parameter of the medium comprises a first parameter and a second parameter, and the using the attribute comprises monitoring the attribute in the TE polarization and in the TM polarization to determine the first and second parameters of the medium. 
     
     
       11. The method of  claim 1 , wherein the waveguide grating includes biologically sensitive material. 
     
     
       12. The method of  claim 1 , wherein the medium is in solid form, liquid form, plasma form, or gas form. 
     
     
       13. The method of  claim 11 , wherein the medium comprises an analyte, a gas, a protein, a micro-organism, a metabolite, a DNA sequence, blood, tissue, or a cell. 
     
     
       14. The method of  claim 1 , wherein the medium comprises a liquid fuel, a gas, or an oil. 
     
     
       15. The method of  claim 1 , wherein the waveguide grating is one among an array of waveguide gratings. 
     
     
       16. A method of using a waveguide grating, comprising:
 contacting a guided-mode resonance waveguide grating with a medium, the guided-mode resonance waveguide grating having at least one waveguide layer and at least one grating layer; 
 directing light having transverse electric (TE) and transverse magnetic (TM) polarizations toward the guided-mode resonance waveguide grating such that the light contacts the guided-mode resonance waveguide grating; 
 determining at least one parameter of the medium using a change in a resonance location in each of the TE and TM polarizations. 
 
     
     
       17. The method of  claim 16 , wherein the at least one waveguide layer and the at least one grating layer comprise the same layer. 
     
     
       18. A method of using a waveguide grating, comprising:
 contacting a guided-mode resonance waveguide grating with a material, the guided-mode resonance waveguide grating being disposed on a substrate and having at least one waveguide layer and at least one grating layer; 
 directing light toward the guide-mode resonance waveguide grating and monitoring a change in an attribute of light that is either reflected from the guided-mode resonance waveguide grating or transmitted through the guided-mode resonance waveguide grating, the change in the attribute corresponding to the addition of a thickness of the material to the guided-mode resonance waveguide grating; 
 where the monitoring involves the use of a detection unit that receives the light that is either reflected or transmitted, the detection unit comprises an optical spectrum analyzer, and the attribute comprises a location of a guided-mode resonance peak or minimum. 
 
     
     
       19. A method of using a waveguide grating, comprising:
 contacting a guided-mode resonance waveguide grating with a material, the guided-mode resonance waveguide grating being disposed on a substrate and having at least one waveguide layer and at least one grating layer; 
 directing light toward the guide-mode resonance waveguide grating and monitoring a change in an attribute of light that is either reflected from the guided-mode resonance waveguide grating or transmitted through the guided-mode resonance waveguide grating, the change in the attribute corresponding to the addition of a thickness of the material to the guided-mode resonance waveguide grating; 
 where the monitoring involves the use of a detection unit that receives the light that is either reflected or transmitted, the attribute comprises a first attribute and a second attribute, the received light has a transverse electric (TE) polarization and a transverse magnetic (TM) polarization, and the monitoring comprises monitoring a change in the first attribute in the TE polarization of the received light and monitoring a change in the second attribute in the TM polarization of the received light to sense the change in the thickness of the material. 
 
     
     
       20. A method of using a waveguide grating, comprising:
 contacting a guided-mode resonance waveguide grating with a material, the guided-mode resonance waveguide grating being disposed on a substrate and having at least one waveguide layer and at least one grating layer; 
 directing light toward the guide-mode resonance waveguide grating and monitoring a change in an attribute of light that is either reflected from the guided-mode resonance waveguide grating or transmitted through the guided-mode resonance waveguide grating, the change in the attribute corresponding to the addition of a thickness of the material to the guided-mode resonance waveguide grating; 
 where the monitoring involves the use of a detection unit that receives the light that is either reflected or transmitted, the received light has a transverse electric (TE) polarization and a transverse magnetic (TM) polarization, and the monitoring comprises monitoring a change in the attribute in the TE polarization and in the TM polarization of the received light to sense the change in the thickness of the material. 
 
     
     
       21. The method of  claim 20 , wherein the monitoring comprises monitoring a change in the attribute in the TE polarization and in the TM polarization of the received light to sense the change in the thickness of the material and to sense a change in another parameter of the material. 
     
     
       22. The method of  claim 1 , wherein the directing comprises directing light through an optical coupler and toward the waveguide grating such that the light contacts the waveguide grating. 
     
     
       23. The method of  claim 11 , wherein the biologically sensitive material comprises a biopolymer, an enzyme, an antibody, DNA, a cell or organic molecules.